Changed the URL(s) (6 posts)

I accidentally changed one of both of the 'Wordpress address (URL)' and 'Blog address (URL)' fields in the general settings page.

When trying to go to the site URL or login page I get "Error establishing a database connection". When I tried to connect to the database to check the values I got "ER_HOST_IS_BLOCKED (1129).
Host'........' is blocked because of many connection errors; unblock with 'mysqladmin flush hosts'"

Also, I replaced the functions.php file with a default version, and added the two required lines. I didn't back up the original file.
I think I made changes to the theme while the site was up - will this be issue?

The "Error establishing a database connection" error message suggests that there is either a problem in your wp-config.php file with the database host name. Or your hosting provider has a problem with their database server. Have you tried contacting theme?

"NOTE: It won't change the Database value though, and the url will revert to the old database value if this line is removed from wp-config. Use the RELOCATE constant to change the siteurl value in the database."